Special Grades HY80

General Characteristics
This is a versatile low-carbon nickel-chromium-molybdenum low-alloy steel that finds use in aggressive environments. It has a good combination of strength and toughness over a wide temperature range, and may be used at temperatures up to 1000ºF (540ºC)

Principal Design Features

HY-80 is a high yield strength (minimum of 80 ksi) , low carbon, low alloy steel with nickel, molybdenum and chromium. It has excellent weldability and notch toughness along with good ductility even in welded sections.

Chemical Analysis

C%	Mn%	Si%	P%	S%	Ni%	Cr%	Mo%
0.12/0.18	0.10/0.40	0.15/0.35	0.025 max	0.025 max	2.00/3.25	1.0/1.8	0.20/0.60

Applications

This material is used in pressure vessels, high-performance pipes and civil construction.

Machinability

Machining of this grade could normally be carried out in the as-forged condition, and finish machining in the quenched and tempered condition, at 80,000 psi yield strength.

Forming

HY-80 may be readily cold or hot formed by conventional bending, or forming, processes. It does exhibit more springback than plain carbon steel so allowance must be made for that when bend forming.

Welding

Weldments of HY-80 are noted for good ductility, notch toughness and strength. It is best welded using the metal-arc process with low hydrogen electrodes of Type E-10018 or E-11018. Use approved weld procedures so as to not apply too much heat input per inch of weld bead, which would otherwise cause degradation of notch toughness. Electrodes should be warmed before use to drive off any moisture to avoid hydrogen pick-up in the weld. Preheating is not required, except for very heavy section thickness welds or heavily constrained welds. Post-heating is not required but a stress relief anneal, after welding of sections of 1-1/2″ thick or greater, is desirable. However the alloy may be used in the as-welded condition.

Weldability
HY 80 shows good weldability in heavy sections, with little preheat and no postweld heat treatment required.

Heat Treatment

This steel gets its strength and toughness combination from a special quench and tempering heat treatment. It is strongly recommended that the actual austenitizing temperature, quenching procedure and tempering temperature be put in the hands of a qualified heat treat provider.

Forging

This grade would be forged at 2100-2200ºF (1150-1205ºC) depending upon amount of reduction to be given. Parts might be air cooled after forging

Annealing

A stress relief anneal may be done at 1200 F for 1 hour per inch of thickness, followed by furnace cooling at a rate not in excess of 200 F per hour down to 500 F. From there it can be air cooled.